1. Field of the Invention
The present invention relates to a technology for waterproof seal members substantially cylindrical such as rubber plugs fitting over end portions of electric wires, and more particularly to a technology for waterproof seal members to fit over end portions of electric wires by directly feeding the waterproof seal members successively toward each electric wire at a high speed by pneumatic means such as the compressed air to remarkably improve the efficiency and the yield in the fitting operation. Hereinafter, the waterproof seal members are merely called as “seal members”.
2. Description of the Related Art
Conventionally, in electric wire connectors of connecting electric wires with each other, an insulative sheath of an electric wire is stripped off to expose a conductor wire, a terminal is crimped to an end portion of the electric wire where the conductor wire is exposed, and then the terminal crimped on the electric wire is fixed in a connector housing. If water or moist is penetrated into the connector housing along the electric wire, the penetrated water may cause short circuit. In order to prevent penetration of water or moist, some connectors have such a waterproof construction that a seal member is mounted on an end portion of an electric wire, and the seal member mounted on the end portion of the electric wire is inserted into a cavity of the connector housing. A seal member, such as a rubber plug is generally a cylindrical-shaped rubber product formed with a lock member passage for passing an electric wire therethrough. The seal member has a multi-step portion on the outer surface thereof.
Various arrangements as disclosed in the below-mentioned prior art documents have been proposed to fit seal members over end portions of electric wires.
Japanese Unexamined Patent Publication No. SHO 60-29249, see FIG. 6, discloses a supporter of angular shape in cross section having a half cylindrical receiving dent at a side of tip portion to receive substantially a cylindrical part of a seal member in an axial direction of an electric wire. The supporter is moved toward the electric wire in a state that a seal member supplied from a magazine be held in the dent, whereby the seal member fits over the tip of the securely fixed electric wire.
Japanese Unexamined Patent Publication No. HEI 5-299149, see FIG. 3, discloses a pair of sticks extending parallel to each other. The sticks are moved closer to a seal member supplied from a magazine for insertion into an lock member passage of the seal member, followed by enlarging the lock member passage by moving the sticks away from each other in order to pass an electric wire through the enlarged lock member passage of the seal member, whereby the seal member fits over an end of the electric wire.
Japanese Unexamined Patent Publication No. HEI 6-189429, see FIGS. 4 through 14, discloses an arrangement provided with a cylinder for inserting a rod into an lock member passage of a seal member by fitting the seal member thereon to supply the seal member to a feeder, means for transporting the seal member held on an end portion of the rod to a holder while pivoting the cylinder by 90°, and a holder for receiving the seal member from the rod to feed the seal member to an electric wire.
Japanese Unexamined Patent Publication No. HEI 11-345668 discloses an arrangement for feeding a seal member by compressed air to be mounted on an end portion of an electric wire.
FIG. 1 is a partially enlarged view of the arrangement disclosed in the above-referenced Japanese Unexamined Patent Publication No. HEI 11-345668, see FIGS. 8 through 15. Referring to FIG. 1, a seal feeding hose 4 is extended from a parts feeder (not shown) and connected with a hose supporting block 3. A seal member 2 to fit over an end portion of an electric wire W is fed inside the seal feeding hose 4 by the compressed air in the direction as shown by the arrow A. A holder supporting block 5 is arranged behind the hose supporting block 3. A seal holder 6 is attached to the holder supporting block 5. After being fed into the seal feeding hose 4, the seal member 2 is seated in a hole 6a in the seal holder 6. At this time, an air suction hose 7 mounted on the other end of the holder supporting block 5 opposite to the seal holder 6 sucks the air inside the hole 6a in the direction shown by the arrow B. Thus, the seal member 2 is kept in close contact with the bottom of the hole 6a. 
Next, as shown in FIG. 2, the holder supporting block 5 is pivoted by 90° in the direction shown by the arrow C to turn the seal member 2 face to a pair of wire guide blocks 8a and 8b. Thereafter, the tip of the electric wire W is passed into an lock member passage of the seal member 2 by moving the electric wire W in the direction shown by the arrow D.
After completion of fitting the seal member 2 over the end portion of the electric wire W, the electric wire W can be taken out by moving the wire guide members 8a and 8b away from each other.
However, both of the arrangements shown in D1 and D2 are configured such that seal members are supplied by the magazine, which makes it difficult to efficiently mount the seal members on end portions of electric wires. Particularly, in D1, it is required to transport a seal member in a state that the seal member is held in the cylindrical receiving dent of the supporter having such a configuration as to correspond to a substantially half part of the seal member. With such an arrangement, it is likely that the held position of the seal member may be inaccurately dislocated during the transportation after the compressed air, thereby lowering the yield in mounting the seal members on the end portions of electric wires.
Further, it is required to pivot the cylinder by 90° in order to transport a seal member from the feeder to the holder in the arrangement disclosed in D3, which takes a time in transportation of the seal member 2.
The arrangement disclosed in D4 is capable of feeding seal members 2 at a high speed by the compressed air. However, each seal member 2 is supplied into the hole 6a of the seal holder 6, in place of using the wire guide blocks 8a and 8b. In addition, it is required to pivot each of the holder supporting block 5, the seal holder 6, and the air suction hose 7 by 90° each time a seal member is mounted on an electric wire. Such an arrangement reduces efficient mounting of seal members onto end portions of electric wires.